    /**
     * @param $
     * 自定义jQuery扩展方法, 在光标处插入内容
     */
    (function ($) {
    	"use strict";
        $.fn.extend({
            insertAtCaret : function (myValue) {
                var $t = $(this)[0];
                if (document.selection) {
                    this.focus();
                    var sel = document.selection.createRange();
                    sel.text = myValue;
                    this.focus();
                } else
                    if ($t.selectionStart || $t.selectionStart == '0') {
                        var startPos = $t.selectionStart;
                        var endPos = $t.selectionEnd;
                        var scrollTop = $t.scrollTop;
                        $t.value = $t.value.substring(0, startPos) + myValue + $t.value.substring(endPos, $t.value.length);
                        this.focus();
                        $t.selectionStart = startPos + myValue.length;
                        $t.selectionEnd = startPos + myValue.length;
                        $t.scrollTop = scrollTop;
                    } else {
                        this.value += myValue;
                        this.focus();
                    }
            }
        });
    })(jQuery);